The revised deal announced Monday also calls for Sprint shareholders to get more cash: $16.6 billion, up from $12.1 billion in the previous offer. Softbank will own about 78 percent of Sprint if the deal is completed, compared with a previous 70 percent.

Satellite TV broadcaster Dish Network Corp. has launched a competing bid it values at $25.5 billion. But Sprint says a special committee of its board has determined Dish will not be able to come up with an offer superior to Softbank's.

Sprint's second largest shareholder, Paulson & Co., says it will vote all its shares in favor of Softbank's sweetened offer.